Additives for improving the diecuttability of diecuttable polyester urethane foam

ABSTRACT

Improved diecuttable polyester urethane foams are provided by the inclusion in the foam formulation of specified minor amounts of certain low molecular weight polyols, typically having hydroxyl numbers of 100 or greater. Representative useful species of such polyols include aliphatic alcohols, such as glycerol and erythritol, polymethylols such as trimethylolpropane, alkanolamines such as triethanolamine and relatively low molecular weight alkylene oxide adducts such as propylene-glycerol adducts and the like. Especially effective diecuttable foam formulations are provided by further employing, as co-additives, certain alkylene oxide adducts of linear alcohols or phenols, sulfonated petroleum oils, ammonium salts and silicone-containing copolymers. If desired, the viscosity and compatibility characteristics of the additive and/or additive and co-additive mixture may be modified by the incorporation of a diluent.

This application is a division of our prior U.S. application Ser. No.645,401, filed Dec. 30, 1975, now U.S. Pat. No. 4,088,615.

BACKGROUND OF THE INVENTION

The present invention relates to diecuttable polyester urethane foamsand, more particularly, to improvements in the diecuttability of suchfoams.

Polyester foams manufactured for use in applications requiring gooddiecuttability, i.e., -- the ability to be diecut or stamped to variousshapes, have a history of variable diecuttability performance.Day-to-day variations in performance have consistently plagued theprocessing of this type of foam.

Typical problems include too slow recovery to the original height of thefoam and permanent edge curl or deformation of the resulting diecutfoam. Perhaps the most severe problem is caused when the edges of thediecut foam have become sealed or welded. These problems areparticularly acute with lower density foams.

The magnitude of the general problem of providing satisfactorilydiecuttable foams has engendered a multitude of theories as to thecauses of good (or poor) diecuttability as well as techniques forimproving diecuttability. Thus, to achieve improved diecuttability, ithas been proposed that: lubrication of the urethane is required, thefoams must be fairly open, course celled foam is better than fine celledfoam, and raising the tolylene diisocyanate index aids as well as othersuggestions. Many manufacturers of polyester foam for diecuttableapplications employ relatively high molecular weight amine compounds asadditives in an attempt to improve diecuttability. Typical of suchadditives include N-coco morpholine (morpholinated coconut oil) andN-lauryl morpholine.

Despite these many suggested techniques and theories, the provision ofconsistently satisfactory polyester foams for diecutting applicationsremains a problem.

While an ostensibly ready solution would be the utilization of polyetherfoams, which typically provide adequate diecuttability, this is notwholly satisfactory. Many and diverse specialty applications (e.g. --hair curlers and the like) require aesthetic foam characteristics notgenerally available when polyether foam formulations are used. Amodification in the foam formulation such as, for example, theparticular isocyanate used, may provide some improvement; but this isgenerally unacceptable due to the associated inventory problems.

The inclusion of low combustibility additives into foam formulations fordiecutting applications has further heightened the problem. The overallresult is that it is estimated that somewhere in the range of about 10to 30 percent of the polyester foam used for commercial diecuttingapplications must be rejected due to unsatisfactory diecuttability. Theaccompanying economic penalty is apparent.

It is thus an object of the present invention to provide a method ofobtaining polyester urethane foams characterized by consistentlyimproved diecuttability. A related object provides polyester urethanefoams possessing improved diecuttability properties even when lowcombustibility additives are employed in the foam formulations.

A still further and specific object of this invention is to providepolyester urethane foams having improved diecuttability characteristicswithout causing any concomitant significant adverse affects on the foamcharacteristics.

Yet another object provides an additive formulation for diecuttablepolyester foams with suitable viscosity and compatibility to allow easyhandling with conventional formulations.

Another object is to provide relatively low density polyester urethanefoams with improved diecuttability properties.

Other objects and advantages of the present invention will becomeapparent from the following detailed description.

While the invention is susceptible to various modifications andalternative forms, there will herein be described in detail thepreferred embodiments. It is to be understood, however, that it is notintended to limit the invention to specific forms disclosed. On thecontrary, it is intended to cover all modifications and alternativeforms falling within the spirit and scope of the invention as expressedin the appended claims. Thus, while the advantageous results of thepresent invention are exemplified herein in connection with certainpolyester foam formulations, it should be appreciated that the presentinvention is equally applicable to use in connection with any polyesterfoams possessing diecuttable properties.

SUMMARY OF THE INVENTION

In general, the present invention is predicated on the discovery thatthe inclusion of certain low molecular weight polyols, typically havinghydroxyl numbers in excess of 100, as additives in specified amounts,consistently provide an improvement in the diecuttabilitycharacteristics of polyester urethane foam when employed as a componentin typical diecuttable polyester urethane foam formulations. Inaccordance with a further aspect of the present invention, it has beenfound that certain co-additives may be used with the specifiedpolyhydroxyl compounds to enhance and aid in the initial recovery afterdiecutting of polyester urethane foams. A concomitant advantage of usingsuch optional co-additives is a reduction in the amount of theisocyanate constituent which must be added in the foam formulation toachieve the requisite diecuttability.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

In accordance with the present invention, the low molecular weightpolyols which have been found to be useful for improving thediecuttability of polyester polyurethane foams fall, in general, intofour categories. The first category comprises aliphatic alcohols havingthe following structural formula: ##STR1## where R₁ may be hydrogen,alkyl (C₁ -C₈), cycloalkyl (C₄ -C₈); R₂ may be hydrogen or alkyl (C₁-C₄); m and p are integer values, m and p may equal zero and the sum ofm and p is 8 or less; and n may assume integer values from 1 to about 4(n=0). Preferred species within this type include glycerol anderythritol. Further illustrative species include sorbitol;1,2,6-hexanetriol; 1,3,5-hexanetriol and 1,2,4-butanetriol.

The second type of suitable additives comprise low molecular weightpolymethylol compounds having the following structural formula: ##STR2##wherein R₁ may be hydrogen, lower alkyl (C₁ to about C₈) or methylol(CH₂ OH). Representative species include trimethylolpropane,pentaerythritol and trimethylolethane. Trimethylolpropane isparticularly preferred.

The third category consists of alkanolamines having the followingstructural formula: ##STR3## wherein R₁ may be H or alkyl (C₁ to aboutC₄) and m and n are zero or may have integral values from one to aboutfour. Illustrative species within this category include diethanolamine,diisopropanolamine and ethanol isopropanol amine, diethanolamine beingpreferred.

The last category comprises alkylene oxide adducts of polyhydroxyalkanesor sucrose. More specifically, this category includes alkylene oxideadducts having a functionality greater than 2 and a minimum hydroxylnumber of about 100, the hydroxyl number preferably being 200 or more.The alkylene oxides may comprise ethylene oxide, propylene oxide,butylene oxide, or mixtures thereof. Polypropylene oxide is preferred;and, when mixtures are employed, the polypropylene oxide content isdesirably 70 percent by weight or greater. Illustrative starters includeglycerol; erythritol; sorbitol; 1,2,6-hexanetriol; 1,3,5-hexanetriol;1,2,4-butanetriol; sucrose; diethylenetriamine; mannitol;1,1,1-trimethylolpropane; pentaerythritol; novolac resins and1,1,1-trimethylolethane. Suitable species include the following: apropylene oxide-glycerol adduct having a hydroxyl number of about 237.5,a propylene oxide-sucrose adduct having a hydroxyl number of about 490and a propylene oxide-diethylenetriamine adduct having a hydroxyl numberof about 700. Still further examples include a propylene oxide-glyceroladduct having a hydroxyl number of about 112.5 and a propyleneoxide-1,2,6-hexanetriol adduct having a hydroxyl number in the range offrom about 200 to 700.

Considering all the categories, it is preferred to utilize glycerol asthe diecuttability-enhancing additive due to its effectiveness andefficiency in use. For example, as may be apparent, the use of thealkylene oxide adducts will require greater amounts than employed withthe lower molecular weight polyols such as glycerol.

Conceptually, the additive should be present in an amount sufficient toimpart improved diecuttability characteristics to the polyester urethanefoam but inadequate to adversely affect, to any significant extent, thefoam characteristics required for the particular end use involved. Theminor amounts required should also be contrasted to the inclusion ofsuch additives in gross amounts that could be considered as changing thecharacter of the foam from a polyester to a polyether or hybrid-type.Also, and, in general, increasing amounts should be utilized as thehydroxyl number of the polyol additive decreases. It has generally beenfound suitable to employ such principal additives in a range of, per 100parts by weight of the polyester polyol used in the foam formulation,0.05 to about 10 parts, preferably 0.1 to about 6.0 parts and, morepreferably, from about 0.2 to about 3.0. The requisite amount can beprovided by using a single principal additive or, if desired, a mixtureof the diecuttability-enhancing additives may suitably be employed.

In accordance with a further aspect of the present invention, certainco-additives may be employed in combination with the aforementioned lowmolecular weight polyhydroxyl compounds to provide the requisiteimproved diecuttability. The utilization of such co-additives allows areduction in the amount of the polyhydroxyl compound required to achievegiven diecuttability characteristics, which in turn allows a decrease inthe amount of the isocyanate which must be added to compensate for theadditional urethane equivalent of the polyhydroxyl compound additive.These co-additives have not been found to impart sufficient improveddiecuttability when used alone but do enhance and aid in providingimproved diecuttability properties when employed together with thehereinbefore described polyhydroxyl principal additives.

Several classes of materials may suitably be utilized as co-additivesand exhibit a synergistic effect when employed with appropriate amountsof the principal additives. More particularly, the use of an additiveand co-additive mixture has, in general, been found to providediecuttability characteristics greater than the effect provided byutilizing comparable amounts of either the principal or co-additivealone. The first class of co-additives comprise alkylene oxide adductsof linear (about C₄ to C₁₅) alcohols and phenols. The moles of thealkylene oxide used to form the adduct, per mole of the linear alcoholor phenol, may vary from about 3 to about 15, preferably 5 to 12. Moreparticularly, suitable materials include ethylene oxide additionproducts to alcohols such as nonylphenol and trisdecanol or other linearalcohols (often present as mixtures). Representative examples withinthis class include ethylene oxide-nonylphenol addition products whereinthe approximate moles of the oxide are 9 and 10.5 and ethyleneoxide-linear alcohol (C₁₁ -C₁₅) products wherein the approximate molesof the oxide are 7 and 9, the last specie (e.g. -- about 9 moles of thelinear alcohol per mole of oxide) being particularly preferred.

Further suitable materials useful as co-additives comprise sulfonatedpetroleum oils and ammonium salts. The sulfonated petroleum oils may beformed by the sulfonation of a hydrocarbon fraction and will typicallyconsist of mixtures of various hydrocarbons. Useful materials arecommercially available and may functionally be characterized assurface-active agents. While the term "sulfonated" has been used, suchmaterials are typically made, as is known, by sulfating the hydrocarbonfraction used by treatment at low temperatures with strong sulfuricacid, with subsequent washing and neutralization of the sulfated mass.More particularly, these liquid, anionic organic surfactants contain atleast one carbon-bonded sulfonic acid group, --SO₃ H, or an ammonium,quaternary ammonium, alkali metal or alkaline earth metal derivative ofsaid sulfonic acid group. The sulfonic acid groups or salt derivativesthereof can be substituents on a wide variety of "backbone" organiccompounds which provide the hydrophobic portion of the emulsifier. Thehydrophobic portion may consist of carbon and hydrogen as in sulfonatedhydrocarbons (or salt derivatives thereof) having from 10 to 20 or morecarbon atoms such as alkanes, high alkyl-substituted benzenes, andliquid petroleum fractions, as typically illustrated by sodiumtetradecyl sulfonate and sodium dodecylbenzene mineral oil. Suitablematerials are commercially available and include sodium sulfonates of ahydrocarbon mixture, "Petronate L" and "Alconate 80" (Witco ChemicalCompany). While only diethylammonium oleate has been employed, otherdialkyl ammonium salts of fatty acid should likewise be useful.

A further class of suitable co-additives comprise silicone copolymersincluding cyanopropyl-substituted, silicone-containing copolymers.Polymethylsiloxane-polyoxyethylene copolymers having the averagecomposition:

    [M].sub.2 [X].sub.x [Y].sub.y [Z].sub.z

wherein the subscripts x, y and z designate the average number of molesof the respective difunctional units contained in the polymer for every2 moles of M, as shown, are useful. In these polymers, x can be zero orany positive number having an average value up to about 20, y has anaverage value from about 2 to about 20 and z has an average value fromabout 2 to about 30, provided the average weight of the polymersattributable to said polyoxyalkylene blocks (E) is from about 50 toabout 85 weight percent. The M, X, Y and Z units have the followingformulae:

    M is (R).sub.3 SiO.sub.1/2

    x is (R).sub.2 SiO.sub.2/2 ##STR4## wherein: R is alkyl; q is zero or one; R° is bivalent alkylene; and E is the aforementioned polyoxyalkylene block. Other useful copolymers are described in U.S. Pat. No. 3,594,334.

A simple co-additive or a mixture may be used with the principalpolyhydroxyl compound or compounds being employed. The relative amountof the co-additive or additives used should be coordinated with theamount of the principal additive to allow achievement of the objectivesof the present invention, viz. -- the improved diecuttability of theresulting polyester foam. Typically, useful levels for the mixture ofthe co-additive with the principal additive will be within the rangeshereinbefore set forth for the principal additive.

As is known, the classes of materials identified as being usefulco-additives have to some extent been previously incorporated intourethane foam formulations for purposes such as foam stabilization andthe like. The levels used have been varied to provide the desired foamproperties. There has, however, been no appreciation that the level ofsuch co-additives could be adjusted in conjunction with the principaladditives of the present invention to impart consistently improveddiecuttability characteristics. Without the inclusion of a principaldiecuttability enhancing additive, an adjustment of the levels ofco-additives, within the constraint of providing the required physicalproperties of the foam, will not achieve consistent improvement in thediecuttability characteristics.

While not essential, it may be desirable in certain situations to adjustthe viscosity and compatibility of the particular additive or additivemixture being employed to facilitate processing with the polyesterpolyol foam formulation being employed. For this purpose, the additivesmay be employed with suitable diluents to yield a blend having thedesired stability, solubility and performance level. As should beapparent, any diluent yielding the desired blend characteristics may beutilized so long as the necessary foam characteristics are not adverselyaffected in any significant extent.

The reactants used to form the polyester urethane foams with which theadditives of the present invention are employed may be varied asdesired. Typically, in addition to the diecuttability enhancingadditives, the foams are prepared by reacting and foaming a reactionmixture of: (a) a polyester polyol reactant containing an average of atleast two hydroxyl groups per molecule; (b) a polyisocyanate reactantcontaining at least two isocyanato groups per molecule; (c) a blowingagent; (d) a catalyst for the reaction of (a) and (b); and (e) a foamstabilizer. As is known, not all polyester foams are suitablydiecuttable; and utilization of the additives of the present inventionwill not necessarily provide sufficient improvement to allow usage indiecutting applications. However, utilizing the additives of the presentinvention will consistently provide improved diecuttability for theproducts resulting from polyester foam formulations typically used fordiecutting applications.

The polyester polyols employed are the reaction products ofpolyfunctional organic carboxylic acids and polyhydric alcohols. Thepolyester polyols contain at least two hydroxyl groups per molecule (asalcoholic OH or as OH in COOH groups). The functionality of these acidsis preferably provided by carboxy groups (COOH) or by both carboxygroups and alcoholic hydroxyl groups. The polyesters have hydroxylnumbers from 30 to 150, and preferably have hydroxyl numbers from 45 to65. As is well known to this art, the hydroxyl numbers are determinedby, and are defined as, the number of milligrams of potassium hydroxiderequired for the complete neutralization of the hydrolysis product ofthe fully acetylated derivative prepared from 1 gram of polyol ormixture of polyols. The hydroxyl number is also defined by the followingequation which indicates its relationship with the molecular weight andfuncationality of the polyol: ##EQU1## wherein

OH = hydroxyl number of the polyol,

f = average functionality, that is, the average number of hydroxylgroups per molecule of polyol, and

M.W. = average molecular weight of the polyol.

Typical of the polyfunctional organic carboxylic acids that can beemployed in producing polyester polyols useful in preparing the foams ofthis invention are: dicarboxylic aliphatic acids such as succinic,adipic, sebacic, azelaic, glutaric, pimelic, malonic, and suberic acids;and dicarboxylic aromatic acids such as phthalic acid, terephthalicacid, isophthalic acid and the like. Other polycarboxylic acids that canbe employed are the "dimer acids" such as the dimer of linoleic acid.Hydroxyl-containing monocarboxylic acids (such as ricinoleic acid) canalso be used. Alternatively, the anhydrides of any of these variousacids can be employed in producing the polyester polyols.

The polyhydric alcohols (organic polyols) that can be employed inproducing the polyester polyol starting material used in the process ofthis invention include the monomeric polyhydric alcohols such as, forexample, glycerol; 1,2,6-hexanetriol; ethylene glycol; diethyleneglycol; trimethylol propane; trimethylolethane; pentaerythritol;1,5-pentanediol; sorbitol; and the like, including mixtures thereof.

Other polyhydric alcohols that can be employed in producing thepolyester polyols useful in preparing the foams of this invention arethe polymeric polyhydric alcohols which include the linear and branchedchain polyethers having a plurality of acyclic ether oxygens and atleast two alcoholic hydroxyl radicals. Illustrative of such polyetherpolyols are the poly (oxyalkylene) polyols containing one or more chainsof connected oxyalkylene radicals which are prepared by the reaction ofone or more alkylene oxides with acyclic and alicyclic polyols. Examplesof the poly (oxyalkylene) polyols include the poly (oxyethylene) glycolsprepared by the addition of propylene oxide to water, propylene glycolor dipropylene glycol; mixed oxyethylene-oxypropylene poly-glycolsprepared in a similar manner utilizing a mixture of ethylene oxide andpropylene oxide or a sequential addition of ethylene oxide and propyleneoxide; and the poly (oxybutylene) glycols and copolymers such as poly(oxyethylene-oxbutylene) glycols and poly (oxypropylene-oxbutylene)glycols. Included in the term "poly (oxybutylene) glycols" are polymersof 1,2-butyleneoxide and 2,3-buytyleneoxide.

Illustrative of further polyester polyol reactants that are useful inproducing flexible polyester urethane foam are the reaction products ofany of the aforesaid polycarboxylic acids and the polyhydric alcoholsprepared by the reaction of one or more alkylene oxides such as ethyleneoxide, propylene oxide, butylene oxide and mixtures thereof, with any ofthe following: glycerol; trimethylolpropane; 1,2,6-hexanetriol;pentaerythritol; sorbitol; glycosides such as methyl, ethyl, propyl,butyl and 2-ethylhexyl arabinoside, xyloside, fructoside, glucoside, andrhammoside; sucrose; mononuclear polyhydroxybenzenes such as resorcinol,pryogallol, phloroglucinol, hydroquinone, 4,6-tertiary-butylcathechol,and catechol; polynuclear hydroxybenzenes ("polynuclear: designating atleast two benzene nuclei") such as di-, tri- and tetra-phenol compoundsin which two to four hydroxybenzene groups are attached either directlyby means of single bonds or through an aliphatic hydrocarbon radicalcontaining one to twelve carbon atoms, such compounds being typicallyillustrated by 2,2-bis (p-hydroxyphenyl)-propane,bis(p-hydroxyphenyl)-methane and the various diphenols and diphenolmethanes disclosed in U.S. Pat. Nos. 2,506,486 and 2,744,882,respectively. Another type of polyester polyol reactant is that producedby reaction of a polycarboxylic acid and the polyether adducts formed byreaction of ethylene oxide, propylene oxide or butylene oxide withphenol-formaldehyde condensation products such as the novolacs.

The organic polyisocyanates that are useful in producing flexiblepolyester urethane foam are organic compounds that contain at least twoisocyanato groups. Such compounds are well known in the art of producingpolyurethane forms, and are conveniently represented by the generalformula:

    Q'(NCO)i

wherein: i has an average value of at least two and is usually no morethan six, and Q' represents an aliphatic, cycloaliphatic or aromaticradical which can be an unsubstituted hydrocarbyl group or a hydrocarbylgroup substituted, for example, with halogen or alkoxy. For example, Q'can be an alkylene, cycloalkylene, arylene, alkyl-substitutedcycloalkylene, arylene, alkyl-substituted cycloalkylene, alkarylene oraralkylene radical including corresponding halogen- andalkoxy-substituted radicals. Typical examples of polyisocyanates for usein preparing the polyurethanes of this invention are any of thefollowing including mixtures thereof: 1,6-hexamethylene diisocyanate;1,4-tetramethylene diisocyanate; 1-methyl-2,4-diisocyanato-cyclohexane;bis(4-isocyanatophenyl)methane; 4-methoxy-1,4-phenylenediisocyanate;4-chloro-1,3-phenylenediisocyanate; 4-bromo-1,3-phenylenediisocyanate;5,6-dimethyl-1,3-phenylenediisocyanate; 2,4-tolylene diisocyanate;2,6-tolylene diisocyanate; mixtures of the 2,4- and 2,6-tolylenediisocyanates; crude tolylene diisocyanates;6-isopropyl-1,3-phenylenediisocyanate; durylene diisocyanate;triphenylmethane-4,4',4"-triisocyanate; and other organicpolyisocyanates known to the polyurethane art. Other suitablepolyisocyanate reactants are ethyl-phosphonic diisocyanate andphenylphosphonic diisocyanate. Of the aforesaid types ofpolyisocyanates, those containing aromatic nuclei are generallypreferred.

Also useful as the polyisocyanate reactant are polymeric isocyanateshaving units of the formula: ##STR5## wherein R'" is hydrogen and/orlower alkyl and j has an average value of at least 2.1. Preferably thelower alkyl radical is methyl and j has an average value of from 2.1 toabout 3.2. Particularly useful polyisocyanates of this type are thepolyphenylmethylene polyisocyanates produced by phosgenation of thepolyamine obtained by acid-catalyzed condensation of aniline withformaldehyde. Polyphenylmethylene polyisocyanates of this type areavailable commercially under such trade names as PAPI, NIAX IsocyanateAFPI, Mondur MR, Isonate 390P, NCO-120, Thanate P-220, NCO-10 andNCO-20. These products are low viscosity (50-100 centipoises at 25° C.)liquids having average iscyanato functionalities in the range of about2.25 to about 3.2 or higher, depending upon the specificaniline-to-formaldehyde molar ratio used in the polyamine preparation.

Other useful polyisocyanates are combinations of diisocyanates withpolymeric isocyanates containing more than two isocyanate groups permolecule. Illustrative of such combinations are: a mixture of2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate and the aforesaidpolyphenylmethylene polyisocyanates and/or polymeric tolylenediisocyanates obtained as residues from the manufacture of thediisocyanates.

On a combined basis, the polyester polyol and organic polyisocyanateusually constitute the major proportion by weight of thepolyurethane-forming reaction mixture. In general, the polyisocyanateand polyester polyol reactants are employed in relative amounts suchthat the ratio of total --NCO equivalents to total active hydrogenequivalent (of the polyester polyol, the additives of the presentinvention and any water, when used) is from 0.8 to 1.5, preferably from1.0 to 1.25, equivalents of --NCO per equivalent of active hydrogen.This ratio is known as the Isocyanate Index and is often expressed as apercent of the stoichiometric amount of polyisocyanate required to reactwith total active hydrogen. When expressed as a percent, the IsocyanateIndex may be from 80 to 150, and is preferably within the range fromabout 100 to about 125.

The amount of the isocyanate constitutent which is added should beadjusted to compensate for the total active hydrogen of the additiveand/or additive and co-additive mixture of the present invention beingutilized to provide the Isocyanate Index which is desired, preferably inthe range as set forth herinbefore.

The urethane-forming reaction is effected in the presence of a minoramount of a catalyst, usually a tertiary amine. Suitable amine catalystsinclude, but are not limited to, one or more of the following:N-methylmorpholine; N-ethylmorpholine; N-octadecylmorpholine;triethylamine, tributylamine; trioctylamineN,N,N',N'-tetramethylethylenediamine;N,N,N',N'-tetramethyl-1,3-butanediamine; triethanolamine;N,N-dimethyl-ethanolamine; triisopropanolamine; N-methyldiethanolamine;triisopropanolamine; N-methyldiethanolamine; hexadecyldimethylamine;N,N-dimethylbenzylamine; trimethylamine;N,N-dimethyl-2-(2-dimethylaminoethoxy)ethylamine, also known asbis(2-dimethylaminoethyl)ether; triethylenediamine (i.e.,1,4-diazabicyclo 2.2.2 octane); the formate and other salts oftriethylenediamine, oxyalkylene adducts of the amino groups of primaryand secondary amines and other such amine catalysts which are well knownin the art of polyurethane manufacture. Also useful are thebetatertiary-amino nitriles wherein the 2-cyanoalkyl group is bonded toacyclic tertiary amino nitrogen or to nitrogen of a morpholine orpiperazine nucleus. Such catalysts are described in copendingapplication Ser. No. 369,556, filed June 13, 1973 of W. R. Rosemund, M.R. Sandner and D. J. Trecker, and are exemplified by3-dimethylamino-propionitrile as such or in combination with othertertiary amines such as bis[2-(N,N-dimethylamino)ethyl]ether. Otheruseful amine catalysts are set forth in U.S. Pat. No. 3,821,131.Although metal-containing catalysts such as stannous octoate are usuallyemployed in the preparation of flexible polyether urethane foam, suchmetal catalysts are not preferred in the manufacture of flexiblepolyester foam.

It is to be understood that the aforesaid amines may be used asessentially the sole amine catalyst of the reaction mixtures employed inthis invention or any combination of two or more such amines may beemployed. The amine catalyst may also be introduced in the reactionmixture in the form of a solvent solution containing from about 10 toabout 80 weight percent of total active catalyst. Suitable carriersolvents of amine catalysts include water-soluble glycols such asdiethylene glycol; dipropylene glycol; and 2-methyl-2,4-pentanediol("hexylene glycol").

It is to be understood that any of the aforesaid amine catalysts orsolutions thereof can be added directly to the foam producing reactionmixture or they can be added in premixed form with water and the foamstabilizers of this invention.

The amine catalyst may, in general, be present in the finalfoam-producing reaction mixture in an amount of from about 0.2 to about8 parts by weight of active catalyst (that is, the amine exclusive ofother components present in the solutions thereof) per 100 parts byweight of the polyester polyol reactant.

Foaming can be accomplished by employing a minor amount of apolyurethane blowing agent such as water, in the reaction mixture, thereaction of water and isocyanate generating carbon dioxide blowingagent, or through the use of blowing agents which are vaporized by theexotherm of the reaction, or by a combination of the two methods. Thesevarious methods are known in the art. Thus, in addition to or in placeof water, other blowing agents which can be employed include methylenechloride, liquified gases which have boiling points below 80° F. andabove -60° F., or other inert gases such as nitrogen, carbon dioxideadded as such, methane, helium and argon. Suitable liquified gasesinclude aliphatic and cycloaliphatic fluorocarbons which vaporize at orbelow the temperature of the foaming mass. Such gases are at leastpartially fluorinated and may also be otherwise halogenated.Fluorocarbon blowing agents suitable for use in foaming the formulationsof this invention include trichloromonofluoromethane,dichlorodifluoromethane, 1,1-dichloro-1-fluoroethane,1,1,1-trifluoro-2-fluoro-3,3-difluoro-4,4,4-trifluorobutane,hexafluorocyclobutene and octafluorocyclobutane. Another useful class ofblowing agents include thermally-unstable compounds which liberate gasesupon heating, such as N,N'-dimethyl-N,N'-dinitrosoterephthalamide, andthe like. The generally preferred method of foaming for producingflexible foams is the use of water or a combination of water plus afluorocarbon blowing agent such as trichloromonofluoromethane.

The amount of blowing agent employed in the foaming reaction will varywith factors such as the density that is desired in the foamed product.Usually, however, from about 1 to about 30 parts by weight of theblowing agent per 100 parts by weight of the polyester polyol startingmaterial is preferred.

As has been described, it is often desirable to utilize lowcombustibility or flame retardant additives. The organic flameretardants that can be employed to form the improved diecuttabilitypolyester foams of the present invention can be chemically combined inone or more of the other reactants used (e.g., in the polyol orpolyisocyanate), or they can be used as discrete chemical compoundsadded as such to the foam formulation. The organic flame retardantspreferably contain phosphorus or halogen, or both phosphorus andhalogen. Usually, the halogen, when present, is chlorine and/or bromine.Flame-retardants of the discrete chemical variety include:2,2-bis(bromomethyl)-1,3-propanediol; 2,3-dibromopropanol;tetrabromophthalic anhydride; brominated phthalate ester diols such asthose produced from tetrabromophthalic anhydride, propylene oxide andpropylene glycol; tetrabromobisphenol-A; 2,4,6-tribromophenol;pentabromophenol; brominated anilines and dianilines;bis(2,3-dibromopropyl) ether of sorbitol; tetrachlorophthalic anhydride;chlorendic acid; chlorendic anhydride; diallyl chlorendate; chlorinatedmaleic anhydride; tris(2-chloroethyl)phosphate; [(ClCH₂ CH₂ O)₃ P(O)];tris (2,3-dibromopropyl)phosphate; tris(1,3-dichloropropyl)phosphate;tris(1-bromo-3-chloroisopropyl)phosphate;tris(1,3-dichloroisopropyl)phosphate; bis(2,3-dibromopropyl) phosphoricacid or salts thereof; oxypropylated phosphoric and polyphosphoricacids; polyol phosphites such as tris(dipropylene glycol)phosphite;polyol phosphonates such as bis(dipropylene glycol)hydroxymethylphosphonate; di-poly(oxyethylene)hydroxymethyl phosphonate;di-poly(oxypropylene)phenyl phosphonate;di-poly(oxypropylene)chloromethyl phosphonate;di-poly(oxypropylene)butyl phosphonate and0,0-diethyl-N,N-bis(2-hydroxyethyl)aminomethyl phosphonate. Alsosuitable are compounds having the formulas: ##STR6## which are availablefrom Monsanto Chemical Company under the names Phosgard 2XC-20 andPhosgard C-22-R, respectively. Other suitable flame-retardants comprisehalogen-containing polymeric resins such as polyvinylchloride resins incombination with antimony trioxide and/or other inorganic metal oxidessuch as zinc oxide, as described in U.S. Pat. Nos. 3,075,927; 3,075,928;3,222,305; and 3,574,149. It is to be understood that otherflame-retardants known to the art may be used and that the aforesaidcompounds may be employed individually or in combination with oneanother.

The flame-retarding agent can be present in the foam formulationsdescribed herein in an amount from about 1 to about 30 parts by weightper 100 parts by weight of the polyester polyol reactant, the particularamount employed depending largely on the efficiency of any given agentin reducing flammability.

Those of the above flame-retardants of the discrete chemical compoundvariety which contain groups reactive with hydroxy or isocyanato groupscan be used as reactants in producing the polyester polyols or can bereacted with organic polyisocyanates to produce modified polyols orpolyisocyanates having chemically combined flame-retardant groups. Suchmodified polyester and polyisocyanates are useful as reactants in theprocess of this invention. In such cases, due regard must be given tothe possible effect of the functionality of the compound on the otherproperties (e.g., degree of flexibility) of the resulting foam.

In producing cellular polyurethanes in accordance with the method ofthis invention, a minor amount of an organosilicone or a silicone-free,organic surfactant may also be present as an additional component of thepolyurethane-forming reaction mixture, organosilicone surfactants beingpreferred. When used, such surfactants are usually present in amounts upto about 5 parts by weight per 100 parts by weight of total polyolreactant.

Suitable classes of silicone surfactants are thepolysiloxane-polyoxyalkylene block copolymers wherein the respectiveblocks are joined through silicon-to-carbon orsilicon-to-oxygen-to-carbon bonds and the respective polyoxyalkyleneblocks are bonded to different silicon atoms of the polysiloxanebackbone to form a comb-like structure. Usually, the polysiloxane blocksare trialkysiloxy-endblocked. In addition to the siloxy units to whichthe pendant polyoxyalkylene chains are bonded, the polysiloxane backboneis formed of difunctional siloxy units wherein the respective tworemaining valences of silicon are satisfied by bonds to organicradicals. Illustrative of such organic radicals are the hydrocarbylgroups having from 1 to 12 carbon atoms including alkyl, aryl, aralkyl,bicycloheptyl and halogen-substituted derivatives of such groups. Thepolyoxyalkylene blocks are usually constituted of oxyethylene units,oxypropylene units or a combination of such units, and thepolyoxyalkylene chains are hydroxyl-terminated or capped with amonovalent organic group such as alkyl, aryl, aralkyl, acyl, carbamyland the like.

A second type of foam-stabilizing component which can be present in theformulations described herein are the branched block copolymersdescribed in U.S. Pat. No. 2,834,748. Organosilicone foam stabilizersdescribed in the latter patent include those containing a trifunctionalsiloxy unit to which three polyoxyalkylene blocks are bonded throughdialkyl-substituted siloxy units. A preferred group are those having theformula, MeSi[OSiMe₂)_(d) (OC_(a) H_(2a))_(b) OR]₃, wherein Me ismethyl, d has a value of at least one, a is from 2 to 3, b has a valueof at least 5, and R is hydrogen or a monovalent hydrocarbyl group suchas lower alkyl, butyl being especially suitable.

Other useful foam-stabilizing components are block copolymers whereinthe polysiloxane blocks are trialkylsiloxy-endblocked and containrecurring difunctional dialkylsiloxy monomeric units in combination withreoccuring difunctional cyanoalkyl-alkylsiloxy orcyanoalkoxy-alkylsiloxy monomeric units, the mole ratio of thedialkylsiloxy units to the cyano-substituted siloxy units being about10-200:3-100, and wherein the polysiloxane and polyoxyalkylene blocksare joined through an Si-C or an Si-O-C linkage, and from about 20 toabout 65 weight percent of the oxyalkylene content of thepolyoxyalkylene blocks is constituted of oxyethylene units. These blockcopolymers are described and claimed in copending application Ser. No.279,883, filed Aug. 11, 1972, in the names of Bela Prokai and BernardKanner. A preferred class of such surfactants are thecyanopropyl-substituted block copolymers having the average formula,##STR7## wherein: Me represents methyl; W represents a monovalenthydrocarbyl group (R'--), an acyl group [R'C(O)--] or a carbamyl group[R'NHC(O)--], the said R' group having from 1 to 12 carbon atoms; x hasan average value of from about 20 to about 100; y has an average valueof from about 4 to about 30; z has an average value of from about 2 toabout 10; a has a value of from 2 to 4, provided from about 20 to about65 weight percent of the oxyalkylene units of the polyoxyalkylene chain,--(C_(a) H_(2a) O)_(b) --, are constituted of oxyethylene; and b has anaverage value such that the average molecular weight of thepolyoxyalkylene chain is from about 1000 to about 6000.

Still further suitable silicon-containing foam stabilizers include thepolysiloxane-polyoxyalkylene block copolymers described, for example, inU.S. Pat. Nos. 3,563,924 and 3,594,334. Such copolymers include thosecharacterized by a particular molecular weight (600-17000), siloxanecontent (14-40 weight percent based on the weight of the copolymer) andoxyethylene content (at least 75 weight percent based on the totalamount of oxyalkylene groups in the copolymer). The organosilicones areusually employed in combination with an anionic, silicon-free organicemulsifier such as those described in said U.S. Pat. No. 3,594,334, theteachings of which are incorporated herein by reference. Also effectiveas stabilizers are the organosilicones containing tetrafunctionalSiO_(4/2) units described and claimed in copending application Ser. No.132,534, filed Apr. 8, 1971, in the names of Bela Prokai and BernardKanner. Of this class of stabilizers, those having the following averageformula are particularly preferred: ##STR8## wherein n has a value of 2to 4 inclusive; d has an average value of from about 5 to about 15; mhas a value of from 2 to 4; a:b:c has an average value of 0.4-2:1:0.2-2,and R'" is phenyl, lower alkyl, lower alkaryl or aryl-substituted loweralkyl grups. Particularly effective are polymers in which at least amajor proportion of the poly(oxyalkylene) chains are terminated byR°°°O-- groups where the organic cap (R°°°) is methyl or benzyl.

Still further useful silicone surfactants includecyanopropyl-substituted polymethylsiloxane-polyoxyehtylene copolymersdescribed in copending application Ser. No. 457,510, filed Apr. 3, 1974,of Bela Prokai and Bernard Kanner. Other useful silicone surfactantscomprise the cyanoalkoxyalkyl-modified polyalkylsiloxane-polyoxyethylenecopolymers described in copending application Ser. No. 536,884, filedDec. 27, 1974, of Bela Prokai and Bernard Kanner.

Silicon-free, organic surfactants or emulsifiers suitable as stabilizersof the polyester polyol-based urethane foams described herein are knownto the art and are employed in amounts up to about 5 p.p.h.p. One classof organic emulsifiers suitable for this purpose are products obtainedby the reaction of amines such as, in particular, diethylamine, withlong chain fatty acids such as oleic acid or with sulfonated C₁₀ -C₁₅alkylated aromatic hydrocarbons. Another class are the liquid, anionicorganic surfactants having at least one carbon-bonded sulfonic acidgroup, --SO₃ H, or an ammonium, quaternary ammonium, alkali metal oralkaline earth metal derivative of said sulfonic acid group. Thesulfonic acid groups or salt derivatives thereof can be substituents ona wide variety of "backbone" organic compounds which provide thehydrophobic portion of the emulsifier. The hydrophobic portion mayconsist of carbon and hydrogen as in sulfonated hydrocarbons (or saltderivatives thereof) having from 10 to 20 or more carbon atoms such asalkanes, high alkyl-substituted benzenes, and liquid petroleumfractions, as typically illustrated by sodium tetradecyl sulfonate,sodium dodecylbenzene sulfonate and sodium and potassium salts ofsulfonated mineral oil. The --SO₃ H group or salt derivative thereof mayalso be a substituent on an organic backbone consisting of carbon,hydrogen and oxygen wherein oxygen is present in an ether linkage as inpolyoxyalkylene groups or in a carboxylic acid ester group. Typical ofsuch compounds are those obtained by sulfating or sulfonatingoxyalkylated fatty acid esters wherein the oxyalkylation is usuallyeffected with ethylene oxide, propylene oxide or a combination thereof.These and other organic stabilizers of polyester polyol-derived urethanefoams are known to the art; see, for example, the description thereof inU.S. Pat. No. 3,594,334.

If desired, other additional ingredients can be employed in minoramounts in producing the polyurethane foams in accordance with theprocess of this invention. Illustrative of such additives that can beemployed are: compression set additives (e.g., hexylene glycol);additives to regulate cell structure so as to coarsen cells and therebyreduce the tendency of the foam to split (e.g., paraffin oil); fillers;dyes; pigments; anti-discoloration additives including anti-scorch andanti-oxidation agents; and the like.

The process described herein for the production of flexible polyesterurethane foam is usually carried out as a "one-shot" process in whichthe polyester polyol and polyisocyanate reactants are independentlyadded to the foam-producing reaction mixture. The foaming andurethane-forming reactions occur without the application of externalheat. Often the resulting foam is cured by heating the foam at atemperature between about 100° C. and about 150° C. for about 10 toabout 60 minutes to eliminate any surfact tackiness, as desired. It isto be understood that variations in process conditions and manipulativesteps can be used as known in the art. For example, the variousingredients of the reaction mixture can be combined and the foamingreaction mixture poured into a mold, or the various ingredients can becombined and the foaming reaction mixture commenced and completed in amold.

The relative amounts of the various components reacted in accordancewith the above-described process for producing flexible polyesterurethane foams are not narrowly critical. The polyester polyol andpolyisocyanate are present in the foam-producing formulation in a majoramount. The relative amounts of these two components is the amountrequired to produce the urethane structure of the foam and such relativeamounts are well known in the art. The source of the blowing action suchas water, auxiliary blowing agents, amine catalyst and theorganosilicone polymeric foam stabilizers are each present in a minoramount necessary to achieve the function of the component. Thus, theblowing agent is present in a minor amount sufficient to foam thereaction mixture, the amine catalyst is present in a catalytic amount(i.e., an amount sufficient to catalyze the reaction to produce theurethane at a reasonable rate), and the additives of the presentinvention are present in an amount sufficient to enhance thediecuttability of the resulting polyester foam. The preferred amounts ofthese various components are as given hereinbefore.

The following examples are merely illustrative of the present inventionand are not intended as a limitation upon the scope thereof. Unlessotherwise indicated, all parts are by weight.

DEFINITIONS

As used in the Examples appearing hereinafter, the followingdesignations, symbols, terms and abbreviations have the indicatedmeanings:

    ______________________________________                                        Resin A      A standard trimethylopropane-based                                            polyester resin having a hydroxyl                                             number of about 50                                               Resin B      A glycerol-based polyester resin                                              having a hydroxyl number of about 50                             Resin C      A triomethylolpropane-based polyester                                         resin having a hydroxyl number of                                             about 60                                                         Catalyst     A mixture of about 95% weight percent                                         3-Dimethyl-aminopropionitrile and                                             5 weight percent bis (2-dimethyl-                                             aminoethyl)ether                                                 Silicone Surfactant                                                                        A composition containing, as the                                              organic silicone surfactant, a cyano-                                         propyl-substituted polymethylsiloxane                                         hydride having the average composition:                           ##STR9##                                                                                  wherein the polyether and siloxane                                            contents are about 68 and 32 weight                                           percent, respectively, present in an                                          amount of about 20 weight percent.                                            The composition also contains, by                                             weight, about 17.5 percent tall oil,                                          10 percent hexylene glycol, 35 percent                                        of an anionic surfactant (a sodium                                            petroleum sulfonate having an average                                         molecular weight of 420 and a mineral                                         content of 33 weight percent), 17.5                                           percent of a non-ionic surfactant (the                                        hydrophobe is a mixture of C.sub.11 -.sub.15 linear                           alcohols and the hydrophile is ethylene                                       oxide present in an average amount of                                         9 mols/mol of hydrophobe) and about                                           2500 ppm 2,6-di-tertiary-butyl-p-cresol.                         Non-ionic surfactant                                                                       The hydrophobe is a mixture of                                                C.sub.11 -C.sub.15 alcohols and the hydrophile                                is ethylene oxide (average amount -                                           9 mols/mol of the hydrophobe)                                    Organic Surfactant A                                                                       Sulfated or sulfonated fatty acid                                             ester, available from Witco Chemical                                          Company, and identified as "77-86"                               Organic Surfactant B                                                                       Diethylammonium oleate, available                                             from Witco Chemical Company or                                                Mobay, and identified as "10-58"                                 Organic Surfactant C                                                                       A proprietary organic surfactant                                              available from Mobay and identified                                           as "6682-A"                                                      Flame Retardant A                                                                           ##STR10##                                                                    available from Monsanto Chemical                                              Company ("Phosgard 2XC-20")                                      Tolylene Diisocyanate                                                         or TDI 80/20 A mixture of about 80 weight percent 2,                                       4-tolylene diisocyanate and about 20                                          weight percent 2,6-tolylene diisocyanate                         TDI BLend 75/25                                                                            A 75/25 weight percent mixture of (a)                                         TDI 80/20 and (b) 65/35 2,4-tolylene                                          diisocyanate and 2,6-tolylene diiso-                                          cyanate                                                          Cream Time (seconds)                                                                       The time in seconds which it takes for                                        the foam-forming mixture to go from a                                         homogeneous clear liquid to a heter-                                          ogeneous milky liquid                                            Rise Time (seconds)                                                                        The time in seconds which it takes the                                        foam to reach its maximum height                                 Breathability                                                                              The porosity of a foam, being roughly                                         proportional to the number of open                                            cells in a foam and being measured                                            in accordance with the NOPCO breath-                                          ability test procedure described by                                           R.E. Jones and G. Fesman, Journal of                                          Cellular Plastics, January, 1965.                                             This is a measure of the air flow                                             through a 2-inch by 2-inch by 1-inch                                          foam sample, expressed as standard                                            cubic feet per minute.                                           Cells Per Inch                                                                             The number of cells per linear inch of                                        the foam, the number being directly                                           proportional to the fineness of the                                           cell structure.                                                  Density      The density of the foam in pounds per                                         cubic foot.                                                      DPG          Dipropylene glycol                                               GLY          Glycerol                                                         ERY          Erythritol                                                       TMP          Trimethylolpropane                                               DEOA         Diethanolamine                                                   TEOA         Trioethanolamine                                                 PPO A        A polypropylene oxide-glycerol adduct                                         having a hydroxyl number of about                                             237.5                                                            PPO B        A polypropylene oxide-sucrose adduct                                          having a hydroxyl number of about 490                            PPO C        A polypropylene oxide-diethylene-                                             triamine adduct having a hydroxyl                                             number of about 700                                              Flame Retardant B                                                                          tris(2,3-dibromopropyl) phosphate                                             available from Michigan Chemical                                              Company and identified as "LVT23P"                               Flame Retardant C                                                                          tris(2-chloroethyl) phosphate avail-                                          able from Stauffer Chemical Company                                           and identified as "CEF"                                          Flame Retardant D                                                                          A polymeric chloroethylphosphate                                              available from Olin Corp. and identi-                                         fied as "Thermolin 101"                                          Co-Additive A                                                                              A sodium petroleum sulfonate anionic                                          surfactant having an average molecular                                        weight of 420 and a mineral content                                           of 33 weight percent                                             Flame Retardant E                                                                          A mixture of tris(2,3-dichloropropyl)                                         phosphate and tris-2(1,3-dichloro-                                            propyl) phosphate, available from                                             Stouffer Chemical Company and identi-                                         fied as "Fyrol FR2"                                              Organic Surfactant D                                                                       An organic surfactant available from                                          Witco Chemical Company and identified                                         as "M-6682-A"                                                    Tensile strength                                                                           ASTM D1564-69                                                    Tear resistance                                                                            ASTM D1564-69                                                    ILD          ASTM D1564-69                                                    Compression Set                                                                            ASTM D1564-69                                                    ______________________________________                                    

Diecuttability Tests

The diecuttability was tested by clicking half-inch sheets with atensile dumbbell die on a United Shoe Machinery Clicker Press. Recoverytime of the foam was measured as percent recovery in less than 15seconds, at 15 seconds, 30 seconds and 60 seconds. Measurements are madeby visual inspection on the cut samples.

Procedure for Preparation of the Polyester Foam

The foam stabilizer, amine catalysts, additives of the present invention(except, of course, where a control was formed) and water were premixedin a beaker. The polyester polyol was weighed into a container, and theisocyanate was then added and mixed with a spatula until homogeneous.Further mixing was done on a drill press equipped with a double3-bladed, marine-type propeller about 3 inches in diameter. The mixingin the drill press was accomplished at 1,000 rpm for about 8 seconds.The premixture of foam stabilizer, amine catalysts, additives and waterwas added and mixing continued for about 7 additional seconds. Thereaction mixture was poured into a one foot by one foot by one footcardboard box and allowed to cure and rise to its maximum height. Thefoam was then postcured for about 30 minutes at 120° C. All the foamswere then removed from the oven and aged overnight at ambienttemperature before being processed and observed for properties.

EXAMPLES 1 TO 11

Several different formulations were tested to provide an indication ofthe extent of the diecuttability problem when low combustabilityadditives are added to typical polyester foam formulations. Examples 1,10 and 11 show the effects of the use of various organic surfactants;Examples 2 and 3 illustrate the effect of increasing the isocyanateindex; Examples 4 and 5 compare increased index with a blend of tolylenediisocyanates; Examples 2, 6 and 7 compare various commercial polyesterresins, and Example 8 illustrates the improvement in diecuttability whenthe low combustibility additive is removed, particularly by comparisonwith Examples 2 and 9.

As can be seen in Table I following, none of the foams in these examplespossess optimum diecuttability characteristics.

                                      TABLE 1                                     __________________________________________________________________________    Example       1   2   3   4   5   6   7   8   9   10  11                      __________________________________________________________________________    Resin Type    A   A   A   A   A   B   C   A   A   A   A                       Resin         100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                   Water         3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6                     Catalyst      2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0                     Hexdecyldimethylamine                                                                       0.30                                                                              0.30                                                                              0.30                                                                              0.30                                                                              0.30                                                                              0.30                                                                              0.30                                                                              0.30                                                                              0.30                                                                              0.30                                                                              0.30                    Silicone Surfactant                                                                         --  1.0 1.0 1.0 1.0 1.0 1.0 1.0 2.0 --  --                      Non-Ionic Surfactant                                                                        --  0.50                                                                              0.50                                                                              0.50                                                                              0.50                                                                              0.50                                                                              0.50                                                                              0.50                                                                              --  --  --                      Organic Surfactant A                                                                        1.6 --  --  --  --  --  --  --  --  --  --                      Organic Surfactant B                                                                        1.0 --  --  --  --  --  --  --  --  --  --                      Organic Surfactant C                                                                        --  --  --  --  --  --  --  --  --  1.0 2.0                     Flame Retardant A                                                                           7.0 7.0 7.0 7.0 7.0 7.0 7.0 --  --  --  --                      Tolylene Diisocyanate                                                                       49.0                                                                              49.0                                                                              53.2                                                                              --  --  49.2                                                                              50.7                                                                              49.0                                                                              46.8                                                                              46.8                                                                              46.8                    TDI Blend 75/25                                                                             --  --  --  49.0                                                                              51.1                                                                              --  --  --  --  --  --                      TDI Index     115 115 125 115 120 115 115 115 110 110 110                     Cream Time, Seconds                                                                         14  13  13  16  13  13  12  11  12  10  11                      Rise Time, Seconds                                                                          93  77  80  85  73  78  70  66  71  56  57                      Breathability, SCFM                                                                         1.3 0.65                                                                              0.45                                                                              0.80                                                                              0.75                                                                              0.50                                                                              0.75                                                                              0.80                                                                              0.85                                                                              0.50                                                                              1.75                    Cells Per Inch                                                                              25-30                                                                             45-50                                                                             45-50                                                                             30-35                                                                             45-50                                                                             45-50                                                                             45-50                                                                             --  45-50                                                                             45-50                                                                             40-45                   Density, pcf  1.92                                                                              1.87                                                                              1.84                                                                              1.86                                                                              1.83                                                                              1.87                                                                              1.83                                                                              1.75                                                                              1.71                                                                              1.78                                                                              1.69                    Diecuttability Recovery, %                                                    after 5-15 Seconds                                                                          --  --  --  --  --  --  --  --  --  --  --                      15 Seconds    20  5   8   10  3   3   50  80  50  5   15                      30 Seconds    55  8   13  20  7   4   87  85  80  10  30                      60 Seconds    75  10  18  55  9   7   95  90  90  15  45                      __________________________________________________________________________

EXAMPLES 12 TO 26

These Examples illustrate the effect of various low molecular weightpolyols on diecuttability. Examples 12-14 illustrate the use ofdipropylene glycol, Examples 15-18 show the use of glycerol, Examples19-20 use erythritol, Example 21 illustrates the use oftrimethylolpropane, Example 22 shows the use of diethanolamine, Example23 uses triethanolamine and Examples 24-26 illustrate the use of variouslow molecular weight polypropylene oxide-based polyols.

The results are set forth in Table II. As can be seen, glycerol providesthe most improvement in diecuttability while erythritol,trimethylolpropane, diethanolamine, and polypropylene oxide adducts Aand C are also effective. Materials such as dipropylene glycol,triethanolamine and polypropylene oxide adduct B were relativelyineffective. In addition, as can be seen from Examples 15-18, the use ofone part glycerol provides excellent initial and final recovery values(Example 15); however, when a low combustibility additive is included,recovery is dimished at 0.6 parts glycerol (Example 16) but is quitesatisfactory at one part (Example 17). A further increase in theisocyanate index to 120 (Example 18) does not significantly improvediecuttability. It is also apparent that the level of enhancement (ifany) of the diecuttability characteristics caused by the additive cannotbe predicted solely on the basis of the hydroxyl number of the additive.

                                      TABLE II                                    __________________________________________________________________________    Example   12  13  14  15 16 17 18 19 20 21 22  23  24  25  26                 __________________________________________________________________________     Resin A Water Catalyst Hexadecyldimethyl- amine Silicone Surfactant          Non-Ionic                                                                                ##STR11##                                                          Surfactant                                                                    Flame Retardant A                                                                       --  7.0 7.0 -- 7.0                                                                              7.0                                                                              7.0                                                                              7.0                                                                              7.0                                                                              7.0                                                                              7.0 7.0 7.0 7.0 7.0                Additive  DPG DPG DPG Gly                                                                              Gly                                                                              Gly                                                                              Gly                                                                              Ery                                                                              Ery                                                                              TMP                                                                              DEOA                                                                              TEOA                                                                              PPOA                                                                              PPOB                                                                              PPOC               Parts     1.8 1.8 0.6 1.0                                                                              0.6                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.5                                                                              1.4                                                                              1.0 1.5 6.0 3.0 2.0                Hydroxyl Number                                                                         836 836 836 1827                                                                             1827                                                                             1827                                                                             1827                                                                             1838                                                                             1838                                                                             1255                                                                             1601                                                                              1128                                                                              238 490 700                Tolylene  51.6                                                                              51.6                                                                              49.8                                                                              52.2                                                                             50.9                                                                             52.2                                                                             54.5                                                                             54.5                                                                             56.2                                                                             52.2                                                                             51.7                                                                              52.0                                                                              51.4                                                                              51.5                                                                              51.5               Diisocyanate                                                                  Index     115 115 115 115                                                                              115                                                                              115                                                                              120                                                                              120                                                                              120                                                                              115                                                                              115 115 115 115 115                Cream Time,                                                                             15  15  14  16 16 16 12 13 15 13 13  13  13  13  7                  seconds                                                                       Rise Time,                                                                              80  87  84  82 86 90 68 77 86 79 80  79  86  83  85                 seconds                                                                       Breathability,                                                                          0.45                                                                              0.45                                                                              0.40                                                                              1.95                                                                             0.95                                                                             0.80                                                                             1.20                                                                             0.85                                                                             1.65                                                                             0.45                                                                             1.15                                                                              0.95                                                                              1.9 0.45                                                                              Top                SCFM                                                                          Cells Per Inch                                                                          45-50                                                                             45-50                                                                             45-50                                                                             -- -- 40-                                                                              -- -- -- 45-                                                                              40-45                                                                             45-50                                                                             --  --  Shrink                                         45          50                                    Density, pcf                                                                            1.85                                                                              1.94                                                                              1.95                                                                              1.64                                                                             1.85                                                                             1.86                                                                             1.86                                                                             1.83                                                                             1.71                                                                             1.80                                                                             1.72                                                                              1.81                                                                              1.95                                                                              1.96                                                                              --                 Diecuttability                                                                Recovery, %                                                                   after 5-15 seconds                                                                      --  --  --  95 -- 90 -- -- -- -- --  --  --  --  --                 15 seconds                                                                              28  5   5   98 73 95 88 40 90 15 20  3   45  10  95                 30 seconds                                                                              73  8   8   99 85 98 98 70 98 25 45  6   75  20  98                 60 seconds                                                                              93  10  9   99 95 98 98 95 99 65 75  7   93  28  98                 __________________________________________________________________________

EXAMPLES 27 TO 34

These Examples illustrate the efficiency of the use of glycerol inenhancing diecuttability characteristics when a variety of lowcombustibility additives are included in the polyester foam formulation.

The results are set forth in Table III. As can be seen, glycerolfunctioned effectively to yield forms of improved diecuttabilityrelative to that expected from similar formulations without glycerol(compare Example 2). Also, in general, as the amount of the lowcombustibility additive was increased, diecuttability wascorrespondingly adversely affected.

                                      TABLE III                                   __________________________________________________________________________    Example     27 28 29  30  31 32  33 34                                        __________________________________________________________________________    Resin A Water Catalyst Hexadecyldimethylamine Silicone Surfactant             Non-Ionic Surfactant                                                                       ##STR12##                                                        Flame Retardant A                                                                         5.0                                                                              10.0   --  -- --  -- --                                        Flame Retardent B                                                                         Retardant                                                                        -- 5.0 10.0                                                                              -- --  -- --                                        Flame Retardant C                                                                         -- -- --  --  5.0                                                                              10.0                                                                              -- --                                        Flame Retardant D                                                                         -- -- --  --  -- --  5.0                                                                              10.0                                       Glycerol TDI Index                                                                        ##STR13##                                                        Cream Time, Seconds                                                                       15 15 15  16  15 15  16 16                                        Rinse Time, Seconds                                                                       86 91 82  86  79 81  78 84                                        Breathability, SCFM                                                                       1.40                                                                             1.35                                                                             1.35                                                                              0.85                                                                              1.0                                                                              2.15                                                                              1.45                                                                             0.75                                      Cells Per Inch                                                                            -- -- --  --  -- --  -- --                                        Density, pcf                                                                              1.75                                                                             1.83                                                                             1.77                                                                              1.89                                                                              1.79                                                                             1.81                                                                              1.70                                                                             1.87                                      Comments    OK OK Scorc                                                                             Scorch                                                                            OK Slight                                                                            OK OK                                                                     Scorch                                           Diecuttability Recover,                                                       % after 5-15 Seconds                                                                      -- -- 90  --  92 --  -- --                                        15 Seconds  40 20 94  13  98 93  58 68                                        30 Seconds  87 63 98  40  99 98  93 90                                        60 seconds  90 90 98  78  99 98  98 97                                        __________________________________________________________________________

EXAMPLES 35 TO 43

These Examples illustrate the use of varying glycerol amounts togetherwith a silicone surfactant. Specifically, glycerol was employed atlevels of 0.5 parts, 0.75 parts and 1.0 parts while the surfactantlevels were 1.0 parts, 1.5 parts and 2.0 parts.

The results are set forth in Table IV. As can be seen, these Examplesillustrate that acceptable diecuttability can be achieved with reducedglycerol levels when the level of the silicone surfactant iscorrespondingly increased.

                                      TABLE IV                                    __________________________________________________________________________    Example       35  36  37  38  39  40  41  42  43                              __________________________________________________________________________    Resin A       100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                           Water         3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6                             Catalyst      2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0                             Hexadecyldimethylamine                                                                      0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3                             Silicone Surfactant                                                                         1.0 1.0 1.0 2.0 2.0 2.0 1.5 1.5 1.5                             Glycerol      0.50                                                                              0.75                                                                              1.0 0.50                                                                              0.75                                                                              1.0 1.0 1.0 0.50                            Flame Retardant A                                                                           7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0                             Tolylene Diisocyanate                                                                       50.7                                                                              51.4                                                                              52.2                                                                              50.7                                                                              51.4                                                                              52.2                                                                              51.4                                                                              52.2                                                                              50.7                            Index         115 115 115 115 115 115 115 115 115                             Cream Time, Seconds                                                                         12  12  12  13  13  13  13  13  13                              Rinse Time, Seconds                                                                         75  77  80  82  86  82  83  90  81                              Breathability, SCFM                                                                         0.90                                                                              2.6 2.5 1.4 1.6 1.3 2.1 2.3 1.25                            Cells Per Inch                                                                              45-50                                                                             40-45                                                                             40-45                                                                             45-50                                                                             45-50                                                                             40-45                                                                             45-50                                                                             40-45                                                                             45-50                           Density, pcf  1.82                                                                              1.73                                                                              1.71                                                                              1.72                                                                              1.73                                                                              1.68                                                                              1.75                                                                              1.72                                                                              1.79                            Diecuttability, Recovery %                                                    after 5-15 Seconds                                                                          --  --  --  --  90  90  --  --  --                              15 Seconds    40  7   38  53  94  94  43  88  10                              30 Seconds    68  50  74  93  98  98  75  98  13                              60 Seconds    90  80  88  98  98  98  93  98  28                              __________________________________________________________________________

EXAMPLES 44 TO 53

These Examples illustrate the use of various petroleum sulfonates (viz.-- Organic surfactant A and Co-additive A) and dialkylammonium oleate(viz. -- Organic surfactant B) as co-additives with glycerol.

The results are set forth in Table V. As can be seen from Examples 46and 47, the use of the co-additives alone does not significantly improvediecuttability relative to the control (Example 44). The use of suchco-additives does however allow the use of a lower level of glycerol tobe employed yet still yielding satisfactorily improved diecuttability.

                                      TABLE V                                     __________________________________________________________________________    Example       44   45  46  47  48  49   50  51  52  53                        __________________________________________________________________________    Resin A       100.0                                                                              100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                              100.0                                                                             100.0                                                                             100.0                                                                             100.0                     Water         3.6  3.6 3.6 3.6 3.6 3.6  3.6 3.6 3.6 3.6                       Catalyst      2.0  2.0 2.0 2.0 2.0 2.0  2.0 2.0 2.0 2.0                       Hexadecyldimethylamine                                                                      0.3  0.3 0.3 0.3 0.3 0.3  0.3 0.3 0.3 0.3                       Silicone Surfactant                                                                         1.0  1.0 1.0 1.0 2.0 1.0  2.0 1.0 1.0 1.0                       Non-ionic Surfactant                                                                        0.5  0.5 0.5 0.5 0.5 0.5  0.5 --  0.5 0.5                       Glycerol      1.0  --  1.0 1.0 --  1.0  0.75                                                                              0.75                                                                              0.75                                                                              0.50                      Co-additive A --   --  --  --  --  --   --  0.50                                                                              0.50                                                                              0.50                      Organic Surfactant A                                                                        --   0.6 0.6 --  --  --   --  --  --  --                        Organic Surfactant B                                                                        --   0.4 0   0.4 --  --   --  --  --  --                        Flame Retardant A                                                                           7.0  7.0 7.0 7.0 7.0 7.0  7.0 7.0 7.0 7.0                       Tolylene Diisocyanate                                                                       52.2 49.0                                                                              52.2                                                                              52.2                                                                              49.0                                                                              52.2 51.4                                                                              51.4                                                                              51.4                                                                              50.7                      Index         115  115 115 115 115 115  115 115 115 115                       Cream Time, seconds                                                                         17   15  17  18  15  13   13  13  13  13                        Rise Time, seconds                                                                          100  86  110 111 88  81   84  87  93  87                        Breathability, SCFM                                                                         1.45 0.60                                                                              2.0 1.75                                                                              1.0 2.2  1.9 0.45                                                                              0.45                                                                              0.65                      Density, pcf  1.78 1.87                                                                              1.85                                                                              1.90                                                                              1.90                                                                              1.74 1.72                                                                              1.70                                                                              1.70                                                                              1.70                      Diecuttability, Recovery %                                                    after 15 seconds                                                                            99   --  90  95  --  85   --  95  --  93                        15 seconds    99   10  99  95  28  98   42  98  75  97                        30 seconds    100  12  100 98  39  98   80  99  88  98                        60 seconds    100  23  100 98  60  98   95  99  95  98                                      Control              Control                                    __________________________________________________________________________

EXAMPLES 54 TO 61

These Examples illustrate the use of glycerol in accordance with thepresent invention together with a petroleum oil sulfonate as aco-additive in a diluent formulation which provides satisfactorycompatibility and reduction in viscosity to permit easy handling. Theblend, identified as "Blend A", is set forth below:

    ______________________________________                                        Component             Weight Percent                                          ______________________________________                                        Glycerol              50                                                      Co-additive A         30                                                      Non-ionic surfactant  15                                                      Organic silicone surfactant                                                    (identified in silicone                                                       surfactant definition)                                                                             5                                                       ______________________________________                                    

Some layering out was observed in the mixture of the additive,co-additive and the organic silicone surfactant; however, addition ofthe non-ionic surfactant eliminated this.

The results are set forth in Table VI. As shown, the use of the blendprovides essentially equivalent overall diecuttability characteristicsto that resulting from the use of the principal additive by itself.Further, as illustrated in Examples 59-61, increases in the isocyanateindex at a constant level of the blend provide only slight improvementsin ultimate diecuttability recovery (i.e.-after 60 seconds).

                                      TABLE VI                                    __________________________________________________________________________    Example       54   55  56  57  58   59  60  61                                __________________________________________________________________________    Resin A       100.0                                                                              100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                              100.0                                                                             100.0                                                                             100.0                             Water         3.6  3.6 3.6 3.6 3.6  3.6 3.6 3.6                               Catalyst      2.0  2.0 2.0 2.0 2.0  2.0 2.0 2.0                               Hexadecyldimethylamine                                                                      0.3  0.3 0.3 0.3 0.3  0.3 0.3 0.3                               Silicone Surfactant                                                                         --   1.0 1.0 1.0 1.0  1.0 1.0 1.0                               Organic Surfactant A                                                                        1.6  --  --  --  --   --  --  --                                Organic Surfactant B                                                                        1.0  --  --  --  --   --  --  --                                Non-ionic Surfactant                                                                        --   --  --  --  0.50 --  --  --                                Glycerol      --   --  --  --  1.0  --  --  --                                Blend A       --   0.75                                                                              1.0 1.25                                                                              --   1.0 1.0 1.0                               Flame Retardant A                                                                           7.0  7.0 7.0 7.0 7.0  7.0 7.0 7.0                               Tolyene Diisocyanate                                                                        49.0 50.1                                                                              50.7                                                                              50.9                                                                              52.2 48.4                                                                              50.6                                                                              52.8                              Index         115  115 115 115 115  110 115 120                               Cream Time, seconds                                                                         14   13  14  14  13   14  13  13                                Rise Time, seconds                                                                          93   82  85  91  82   86  86  88                                Breathability, SCFM                                                                         1.30 1.15                                                                              1.20                                                                              1.25                                                                              2.45 0.65                                                                              1.45                                                                              1.35                              Density, pcf  1.92 1.74                                                                              1.70                                                                              1.72                                                                              1.71 1.83                                                                              1.72                                                                              1.72                              Diecuttability, Recovery %                                                    after 15 seconds                                                                            --   --  --  --  90   --  --  88                                15 seconds    22   40  30  85  94   25  44  94                                30 seconds    55   80  40  97  98   63  85  98                                60 seconds    78   97  80  98  98   90  97  98                                              Control          Control                                        __________________________________________________________________________

EXAMPLES 62 TO 71

The effect on diecuttability due to the addition of n-coco morpholine incontrast to the enhancement imparted by an additive according to thepresent invention is illustrated.

The results are set forth in Table VII. As can be seen, the addition ofn-coco morpholine does not improve the diecuttability in either a systemstabilized with a surfactant (compare Examples 62 and 63) or in systemshaving a glycerol additive in accordance with the present invention(compare Examples 64 and 65). In contrast, the substitution of Blend Ais effective in improving diecuttability in accordance with the presentinvention when used in place of n-coco morpholine in an organicsurfactant stabilized foam (compare Example 68 with Example 69). Furtheradvantage may perhaps be evident from the fact that the density of thefoam containing Blend A is also lower than that containing n-cocomorpholine.

                                      Table VII                                   __________________________________________________________________________    Examples      62   63  64   65  66   67  68  69  70   71                      Resin A       100.0                                                                              100.0                                                                             100.0                                                                              100.0                                                                             100.0                                                                              100.0                                                                             100.0                                                                             100.0                                                                             100.0                                                                              100.0                   Water         3.6  3.6 3.6  3.6 3.6  3.6 3.6 3.6 4.0  4.0                     Catalyst      2.0  2.0 2.0  2.0 2.0  2.0 2.0 2.0 2.5  2.5                     Hexadecyldimothylamine                                                                      0.3  0.3 0.3  0.3 0.3  0.3 0.3 0.3 0.40 0.40                    Silicone Surfactant                                                                         1.0  1.0 1.0  1.0 1.0  1.0 --  --  1.0  1.0                     Organic Surfactant A                                                                        --   --  --   --  --   --  1.6 1.6 --   --                      Organic Surfactant B                                                                        --   --  --   --  --   --  1.0 1.0 --   --                      n-coco morpholine                                                                           --   1.0 --   1.0 --   --  1.0 --  --   --                      Non-ionic Surfactant                                                                        0.5  0.5 0.5  0.5 --   --  --  --  --   --                      Glycerol      --   --  1.0  1.0 --   --  --  --  --   --                      Blend A       --   --  --   --  --   1.0 0   1.0 --   1.0                     Flame Retardant A                                                                           7.0  7.0 7.0  7.0 --   --  7.0 7.0 --   --                      TDI 80/20     51.1 51.1                                                                              52.2 52.2                                                                              49.0 50.7                                                                              49.0                                                                              50.7                                                                              51.0 54.9                    Index         120  120 115  115 115  115 115 115 110  115                     Cream Time, seconds                                                                         12   10  15   13  12   14  13  16  11   12                      Rise Time, seconds                                                                          81   69  89   77  67   77  81  101 57   60                      Breathability, SCFM                                                                         0.55 0.40                                                                              1.3  0.80                                                                              0.45 1.20                                                                              0.85                                                                              1.25                                                                              0.55 1.0                     Density, pcf  1.89 2.08                                                                              1.79 1.82                                                                              1.76 1.60                                                                              1.95                                                                              1.81                                                                              1.68 1.50                    Diecuttability, Recovery %                                                    after 15 seconds                                                                            --   --  90   --  --   --  88  90  --   97                      15 seconds    30   30  93   80  4    87  89  98  0    98                      30 seconds    50   40  97   93  7    97  98  98  0    99                      60 seconds    80   45  98   98  12   98  98  99  3    100                                   Control  Control  Control          Control                      __________________________________________________________________________

EXAMPLES 72-81

These Examples illustrate the enhancement of diecuttabilitycharacteristics on machine-made foams in contrast to other priortechniques.

The foams were prepared as follows. To a Hennecke UBT-63 high pressurecontinuous polyurethane foam machine, there was fed: (1) the polyesterpolyol stream; (2) an activator stream containing water, amine catalystand foam stabilizing surfactant; (3) a polyisocyanate stream; (4) a lowcombustibility additive stream (when used) and (5) the additive stream.The mixer speed was about 5000 revolutions per minute, and the headpressure was about 15 pounds per square inch. The foams were allowed toset and cure. After 24 hours of aging at ambient temperature, the foamsare cut and submitted for physical property measurements.

The foam formulations used and the results are set forth in Table VIII.As can be seen, the use of the present invention provides improveddiecuttability characteristics, resulting in some formulations ininstaneous recovery. The physical properties of the resulting foams werealso acceptable.

                                      TABLE VIII                                  __________________________________________________________________________    Example       72  73  74  75  76  77  78  79  80  81                          __________________________________________________________________________    Resin A       100 100 100 100 100 100 100 100 100 100                         Water         3.6 3.6 3.6 3.6 3.6 3.6 3.6 3.6 4.0 4.2                         Catalyst      2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0                         Hexadecyldimethylamine                                                                      0.25                                                                              0.25                                                                              0.25                                                                              0.25                                                                              0.25                                                                              0.25                                                                              0.25                                                                              0.25                                                                              0.30                                                                              0.30                        Silicone Surfactant                                                                         1.0 1.0 1.0 1.0 1.0 1.0 1.0 --  1.0 1.0                         Organic Surfactant D                                                                        --  --  --  --  --  --  --  1.5 --  --                          Blend A (with Ionol                                                                         --  0.50                                                                              --  1.0 1.5 2.5 2.0 --  1.5 1.5                         added 500 ppm)                                                                N-Coco-Morpholine                                                                           --  --  --  --  --  --  --  1.0 --  --                          Flame Retardant E                                                                           --  --  7.0 7.0 7.0 7.0 7.0 7.0 7.0 7.0                         TDI           49.0                                                                              49.8                                                                              49.0                                                                              50.6                                                                              51.3                                                                              53.0                                                                              49.9                                                                              49.0                                                                              55.8                                                                              58.1                        Index         115 115 115 115 115 115 110 115 115 115                         Density, pcf  1.68                                                                              1.84                                                                              1.79                                                                              1.68                                                                              1.74                                                                              1.74                                                                              1.68                                                                              1.80                                                                              1.58                                                                              1.54                        Breathability, SFCM                                                                         0.85                                                                              0.60                                                                              0.80                                                                              0.70                                                                              0.40                                                                              0.80                                                                              0.35                                                                              0.30                                                                              0.29                                                                              0.35                        Cells Per Inch                                                                              35-40                                                                             35-40                                                                             35-40                                                                             30-35                                                                             30-35                                                                             25-30                                                                             45-50                                                                             30-35                                                                             30-35                                                                             35-40                       ILD, 25       55.0                                                                              48.7                                                                              53.2                                                                              62.9                                                                              65.8                                                                              53.4                                                                              49.9                                                                              57.0                                                                              56.5                                                                              61.5                           65         98.9                                                                              87.7                                                                              97.8                                                                              130.0                                                                             149.5                                                                             96.0                                                                              100.2                                                                             112.5                                                                             113.8                                                                             147.5                       Compression Set, 75/90                                                                      12.6/                                                                             17.3/                                                                             17.5/                                                                             48.2/                                                                             60.2/                                                                             15.4/                                                                             36.7/                                                                             8.831                                                                             28.2/                                                                             73.0/                                     16.6                                                                              21.5                                                                              36.7                                                                              81.8                                                                              70.8                                                                              22.3                                                                              29.7                                                                              11.3                                                                              41.4                                                                              72.1                        Tensile Strength                                                                            23.0                                                                              27.9                                                                              23.7                                                                              23.0                                                                              21.6                                                                              19.7                                                                              22.6                                                                              24.3                                                                              21.4                                                                              22.9                        Elongation %  232 272 260 139 130 172 216 260 173 167                         Tear Strength 2.9 3.3 3.35                                                                              1.69                                                                              1.75                                                                              2.21                                                                              2.67                                                                              3.40                                                                              1.93                                                                              2.44                        Diecuttability, Recovery                                                      % after 60 seconds                                                            1/2Inch Sample                                                                              65-70                                                                             85-90                                                                             65-70                                                                             IR.sup.I                                                                          IR  100 99  98.sup.2                                                                          100 100                         1/4Inch Sample                                                                              --  --  --  IR  IR  99  99  85-90                                                                             100 100                         1/8Inch Sample                                                                              --  --  --  IR  IR  95  98  85-90.sup.3                                                                       100 99-100                      __________________________________________________________________________     .sup.1 Instaneous recovery - 1/2inch and 1/4inch samples (Ex. 75 only)        also achieved instaneous recovery in 30 seconds.                              .sup.2 95-98 in 30 seconds.                                                   .sup.3 45-50 in 30 seconds.                                              

Thus, as has been seen, the present invention provides polyesterurethane foams having improved diecuttability characteristics, even whenlow combustibility additives are present. These improved results areachieved without any significant adverse effects on the resulting foamproperties. The initial tensile strength of foams made in accordancewith the present invention is lowered; but it appears that the tensilevalues, after aging, have decreased significantly less than whenconventional foam formulations are used. The utilization of increasingamounts of the diecuttability enhancing additives of the presentinvention correspondingly diminishes this loss in tensile strength afteraging to the extent that in some instances, the value is substantiallythe same as the initial value.

It should be appreciated that day-to-day variations often create adverseeffects on diecuttability. While the present invention may not in everyinstance impart sufficient enhancement to completely compensate, theutilization of the present invention has been found to consistentlyprovide improvement in comparison to foams not formulated in accordancewith this invention. Further, while the present invention is directed topolyester-based urethane foams, the foam formulations, as may beappreciated, can include minor amounts of polyether polyols or the likeas long as the resulting urethane foam retains the polyestercharacteristics required for the particular end use involved.

What is claimed is:
 1. An additive mixture for improving thediecuttability characteristics of diecuttable polyester urethane foamwhich comprises (a) a diecuttability enhancing additive comprising a lowmolecular weight polyol selected from the groups consisting of (1) analiphatic alcohol having the following structural formula: ##STR14##wherein R₁ may be hydrogen, alkyl (C₁ -C₈), or cycloalkyl (C₄ -C₈); R₂may be hydrogen or alkyl (C₁ -C₄); m and p are integer values, m and pmay equal zero and the sum of m and p is 8 or less; and n may assumeinteger values from 1 to about 4; (2) a low molecular weightpolymethylol compound having the following structural formula: ##STR15##wherein R₁ may be hydrogen, lower alkyl (C₁ to about C₈) or methylol(CH₂ OH); (3) an alkanolamine having the following structural formula:##STR16## wherein R₁ may be H or alkyl (C₁ to about C₄) and m and n arezero or may have integral values from one to about four; (4) alkyleneoxide adducts having a functionality greater than 2 and a minimumhydroxyl number of about 100, and (5) mixtures thereof; (b) aco-additive being present in an amount sufficient to improve thediecuttability characteristics of diecuttable polyester foam; (c) asilicone surfactant; and (d) a diluent present in an amount sufficientto lower the viscosity of the mixture of (a), (b) and (c); said additivemixture being stable and having no tendency to layer out.
 2. An additivemixture for improving the diecuttability characteristics of diecuttablepolyester urethane foam which comprises (a) a diecuttability enhancingadditive consisting of an aliphatic alcohol having the followingstructural formula: ##STR17## wherein R₁ may be hydrogen, alkyl (C₁-C₈), or cycloalkyl (C₄ -C₈); R₂ may be hydrogen or alkyl (C₁ -C₄); mand p are integer values, m and p may equal zero and the sum of m and pis 8 or less; and n may assume integer values from 1 to about 4; (b) aco-additive consisting of a sulfonated petroleum oil; saiddiecuttability enhancing additive and co-additive being present in anamount sufficient to improve the diecuttability characteristics ofdiecuttable polyester foam; (c) a silicone surfactant; and (d) anon-ionic surfactant present in an amount sufficient to reduce theviscosity of the mixture of (a), (b) and (c); said additive mixturebeing stable and having no tendency to layer out.
 3. An additive mixturefor improving the diecuttability characteristics for diecuttablepolyester urethane foam which comprises (a) glycerol; (b) a sodiumpetroleum sulfonate anionic surfactant having a average molecular weightof 420 and a mineral content of 33 weight percent; said glycerol andanionic surfactant being present in an amount sufficient to improve thediecuttability characteristics of diecuttable polyester foam; (c) acyanopropyl-substituted polymethylsiloxane hydride silicone surfactanthaving the average composition: ##STR18## and (d) a non-ionic surfactantwherein the hydrophobe is a mixture of C₁₁ -C₁₅ linear alcohols and thehydrophile is ethylene oxide present in an average amount of 9 mols/molof hydrophobe; said non-ionic surfactant being present in an amountsufficient to lower the viscosity of the mixture of (a), (b) and (c) andsaid additive mixture being stable and having no tendency to layer out.